Virtual testing and inspection of a virtual weldment

ABSTRACT

Arc welding simulations that provide simulation of virtual destructive and non-destructive testing and inspection of virtual weldments for training purposes. The virtual testing simulations may be performed on virtual weldments created using a virtual reality welding simulator system (e.g., a virtual reality arc welding (VRAW) system). The virtual inspection simulations may be performed on “pre-canned” (i.e. pre-defined) virtual weldments or using virtual weldments created using a virtual reality welding simulator system. In general, virtual testing may be performed using a virtual reality welding simulator system (e.g., a virtual reality arc welding (VRAW) system), and virtual inspection may be performed using a standalone virtual weldment inspection (VWI) system or using a virtual reality welding simulator system (e.g., a virtual reality arc welding (VRAW) system). However, in accordance with certain enhanced embodiments of the present invention, virtual testing may also be performed on a standalone VWI system.

This U.S. patent application claims priority to and is acontinuation-in-part (CIP) patent application of pending U.S. patentapplication Ser. No. 12/501,257 filed on Jul. 10, 2009 which isincorporated herein by reference in its entirety. This U.S. patentapplication also claims priority to U.S. provisional patent applicationSer. No. 61/349,029 filed on May 27, 2010 which is incorporated hereinby reference in its entirety.

TECHNICAL FIELD

Certain embodiments relate to virtual reality simulation. Moreparticularly, certain embodiments relate to systems and methods forvirtual testing and inspection of a virtual weldment for training ofwelders, welding inspectors, welding educators, structural engineers,and material engineers.

BACKGROUND

In real world welding and training, a weldment may be subjected to adestructive test and/or a non-destructive test. Such tests help todetermine the quality of the weldment and, therefore, the ability of thewelder. Unfortunately, certain types of non-destructive tests such as,for example, X-ray radiographic testing, can require expensive testequipment and it can be time consuming to perform the tests.Furthermore, destructive tests, by definition, destroy the weldment. Asa result, the weldment can only be tested once in a destructive test.Also, a large gap exists in the industry between making a weldment andknowing if the weld is a good weld. Welding inspection training oftenrelies on such destructive and non-destructive tests to properly train awelding inspector to determine how good or bad a weldment may be. TheAmerican Welding Standard (AWS), as well as other welding standardbodies, provides visual inspection standards that set criterion as tothe types and levels of discontinuities and defects that are allowed ina particular type of weldment.

Further limitations and disadvantages of conventional, traditional, andproposed approaches will become apparent to one of skill in the art,through comparison of such approaches with embodiments of the presentinvention as set forth in the remainder of the present application withreference to the drawings.

SUMMARY

Arc welding simulations that provide simulation of virtual destructiveand non-destructive testing and inspection and materials testing ofvirtual weldments for training purposes are disclosed herein. Thevirtual testing simulations may be performed on virtual weldmentscreated using a virtual reality welding simulator system (e.g., avirtual reality arc welding (VRAW) system). The virtual inspectionsimulations may be performed on “pre-canned” (i.e. pre-defined) virtualweldments or using virtual weldments created using a virtual realitywelding simulator system. In general, virtual testing may be performedusing a virtual reality welding simulator system (e.g., a virtualreality arc welding (VRAW) system), and virtual inspection may beperformed using a standalone virtual weldment inspection (VWI) system orusing a virtual reality welding simulator system (e.g., a virtualreality arc welding (VRAW) system). However, in accordance with certainenhanced embodiments of the present invention, virtual testing may alsobe performed on a standalone VWI system. In accordance with anembodiment of the present invention, the standalone VWI system is aprogrammable processor-based system of hardware and software withdisplay capability. In accordance with another embodiment of the presentinvention, the VRAW system includes a programmable processor-basedsubsystem, a spatial tracker operatively connected to the programmableprocessor-based subsystem, at least one mock welding tool capable ofbeing spatially tracked by the spatial tracker, and at least one displaydevice operatively connected to the programmable processor-basedsubsystem. The VRAW system is capable of simulating, in virtual realityspace, a real time welding scenario including formation of a weldment bya user (welder) and various defect and discontinuity characteristicsassociated with the weldment. Both the standalone VWI system and theVRAW system are capable of performing virtual inspection of a virtualweldment and displaying an animation of the virtual weldment underinspection to observe the effects. The VRAW system is capable ofperforming both virtual testing and virtual inspection of a virtualweldment and displaying an animation of the virtual weldment under testor inspection. A virtual weldment may be tested and inspected over andover again, destructively and non-destructively, using the correspondingvirtual reality welding simulator system or the corresponding standalonevirtual weldment inspection system.

These and other features of the claimed invention, as well as details ofillustrated embodiments thereof, will be more fully understood from thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example embodiment of a system block diagram of asystem providing arc welding training in a real-time virtual realityenvironment;

FIG. 2 illustrates an example embodiment of a combined simulated weldingconsole and observer display device (ODD) of the system of FIG. 1;

FIG. 3 illustrates an example embodiment of the observer display device(ODD) of FIG. 2;

FIG. 4 illustrates an example embodiment of a front portion of thesimulated welding console of FIG. 2 showing a physical welding userinterface (WUI);

FIG. 5 illustrates an example embodiment of a mock welding tool (MWT) ofthe system of FIG. 1;

FIG. 6 illustrates an example embodiment of a table/stand (T/S) of thesystem of FIG. 1;

FIG. 7A illustrates an example embodiment of a pipe welding coupon (WC)of the system of FIG. 1;

FIG. 7B illustrates the pipe WC of FIG. 7A mounted in an arm of thetable/stand (TS) of FIG. 6;

FIG. 8 illustrates various elements of an example embodiment of thespatial tracker (ST) of FIG. 1;

FIG. 9A illustrates an example embodiment of a face-mounted displaydevice (FMDD) of the system of FIG. 1;

FIG. 9B is an illustration of how the FMDD of FIG. 9A is secured on thehead of a user;

FIG. 9C illustrates an example embodiment of the FMDD of FIG. 9A mountedwithin a welding helmet;

FIG. 10 illustrates an example embodiment of a subsystem block diagramof a programmable processor-based subsystem (PPS) of the system of FIG.1;

FIG. 11 illustrates an example embodiment of a block diagram of agraphics processing unit (GPU) of the PPS of FIG. 10;

FIG. 12 illustrates an example embodiment of a functional block diagramof the system of FIG. 1;

FIG. 13 is a flow chart of an embodiment of a method of training usingthe virtual reality training system of FIG. 1;

FIGS. 14A-14B illustrate the concept of a welding pixel (wexel)displacement map, in accordance with an embodiment of the presentinvention;

FIG. 15 illustrates an example embodiment of a coupon space and a weldspace of a flat welding coupon (WC) simulated in the system of FIG. 1;

FIG. 16 illustrates an example embodiment of a coupon space and a weldspace of a corner (tee joint) welding coupon (WC) simulated in thesystem of FIG. 1;

FIG. 17 illustrates an example embodiment of a coupon space and a weldspace of a pipe welding coupon (WC) simulated in the system of FIG. 1;

FIG. 18 illustrates an example embodiment of the pipe welding coupon(WC) of FIG. 17;

FIGS. 19A-19C illustrate an example embodiment of the concept of adual-displacement puddle model of the system of FIG. 1;

FIG. 20 illustrates an example embodiment of a standalone virtualweldment inspection (VWI) system capable of simulating inspection of avirtual weldment and displaying an animation of the virtual weldmentunder inspection to observe the effects due to various characteristicsassociated with the weldment;

FIG. 21 illustrates a flow chart of an example embodiment of a method toassess the quality of a rendered baseline virtual weldment in virtualreality space; and

FIGS. 22-24 illustrate embodiments of virtual animations of a simulatedbend test, a simulated pull test, and a simulated break test for a samevirtual section of a weldment.

DETAILED DESCRIPTION

An embodiment of the present invention comprises a system for thevirtual testing and inspecting of a virtual weldment. The systemincludes a programmable processor-based subsystem operable to executecoded instructions. The coded instructions include a rendering engineand an analysis engine. The rendering engine is configured to render atleast one of a three-dimensional (3D) virtual weldment before simulatedtesting, a 3D animation of a virtual weldment under simulated testing,and a 3D virtual weldment after simulated testing. The analysis engineis configured to perform simulated testing of a 3D virtual weldment. Thesimulated testing may include at least one of simulated destructivetesting and simulated non-destructive testing. The analysis engine isfurther configured to perform inspection of at least one of a 3D virtualweldment before simulated testing, a 3D animation of a virtual weldmentunder simulated testing, and a 3D virtual weldment after simulatedtesting for at least one of pass/fail conditions anddefect/discontinuity characteristics. The system also includes at leastone display device operatively connected to the programmableprocessor-based subsystem for displaying at least one of a 3D virtualweldment before simulated testing, a 3D animation of a virtual weldmentunder simulated testing, and a 3D virtual weldment after simulatedtesting. The system further includes a user interface operativelyconnected to the programmable processor-based subsystem and configuredfor at least manipulating an orientation of at least one of a 3D virtualweldment before simulated testing, a 3D animation of a virtual weldmentunder simulated testing, and a 3D virtual weldment after simulatedtesting on the at least one display device. The programmableprocessor-based subsystem may include a central processing unit and atleast one graphics processing unit. The at least one graphics processingunit may include a computer unified device architecture (CUDA) and ashader. The analysis engine may include at least one of an expertsystem, a support vector machine (SVM), a neural network, and one ormore intelligent agents. The analysis engine may use welding code dataor welding standards data to analyze at least one of a 3D virtualweldment before simulated testing, a 3D animation of a virtual weldmentunder simulated testing, and a 3D virtual weldment after simulatedtesting. The analysis engine may also include programmed virtualinspection tools that can be accessed and manipulated by a user usingthe user interface to inspect a virtual weldment.

Another embodiment of the present invention comprises a virtual weldingtesting and inspecting simulator. The simulator includes means forperforming one or more simulated destructive and non-destructive testson a rendered 3D virtual weldment. The simulator also includes means foranalyzing results of the one or more simulated destructive andnon-destructive tests on the rendered 3D virtual weldment. The simulatorfurther includes means for inspecting the rendered 3D virtual weldmentat least after a simulated test of the 3D virtual weldment. Thesimulator may also include means for rendering a 3D virtual weldment.The simulator may further include means for rendering a 3D animation ofthe virtual weldment while performing the one or more simulateddestructive and non-destructive tests. The simulator may also includemeans for displaying and manipulating an orientation of the 3D animationof the virtual weldment. The simulator may further include means forinspecting a 3D virtual weldment before, during, and after simulatedtesting of the 3D virtual weldment.

A further embodiment of the present invention comprises a method ofassessing the quality of a rendered baseline virtual weldment in virtualreality space. The method includes subjecting the baseline virtualweldment to a first computer-simulated test configured to test at leastone characteristic of the baseline virtual weldment. The method alsoincludes rendering a first tested virtual weldment and generating firsttest data in response to the first test. The method further includessubjecting the first tested virtual weldment and the first test data toa computer-simulated analysis configured to determine at least onepass/fail condition of the first tested virtual weldment with respect tothe at least one characteristic. The first computer-simulated test maysimulate a real-world destructive test or a real-world non-destructivetest. The method may further include re-rendering the baseline virtualweldment in virtual reality space, subjecting the baseline virtualweldment to a second computer-simulated test configured to test at leastone other characteristic of the baseline virtual weldment, rendering asecond tested virtual weldment and generating second test data inresponse to the second test, and subjecting the second tested virtualweldment and the second test data to a computer-simulated analysisconfigured to determine at least one other pass/fail condition of thesecond tested virtual weldment with respect to the at least one othercharacteristic. The second computer-simulated test may simulate areal-world destructive test or a real-world non-destructive test. Themethod may further include manually inspecting a displayed version ofthe rendered first tested virtual weldment. The method may also includemanually inspecting a displayed version of the rendered second testedvirtual weldment.

A completed virtual weldment formed in virtual reality space may beanalyzed for weld defects and a determination may be made as to whetheror not such a weldment would pass or fail standard industry tests, inaccordance with an embodiment of the present invention. Certain defectsmay cause certain types of failures within certain locations within theweldment. The data representing any defects or discontinuities iscaptured as part of the definition of the virtual weldment either bypre-defining the virtual weldment or by creating a virtual weldmentusing a virtual reality welding simulator system (e.g., a virtualreality arc welding (VRAW) system) as part of a virtual welding process.

Also, criterion for pass/fail of any particular test is known aprioribased on predefined welding codes and standards such as, for example,the AWS welding standards. In accordance with an embodiment of thepresent invention, an animation is created allowing visualization of asimulated destructive or non-destructive test of the virtual weldment.The same virtual weldment can be tested many different ways. Testing andinspection of a virtual weldment may occur on a virtual reality weldingsimulator system (e.g., a virtual reality arc welding (VRAW) system)which is described in detail later herein. Inspection of a virtualweldment may occur on a standalone virtual weldment inspection (VWI)system which is described in detail later herein.

The VRAW system is capable of allowing a user to create a virtualweldment in real time by simulating a welding scenario as if the user isactually welding, and capturing all of the resultant data which definesthe virtual weldment, including defects and discontinuities. The VRAWsystem is further capable of performing virtual destructive andnon-destructive testing and inspection of the virtual weldment as wellas materials testing and inspection of the virtual weldment. Thestandalone VWI system is capable of inputting a predefined virtualweldment or a virtual weldment created using the VRAW system, andperforming virtual inspection of the virtual weldment. Athree-dimensional virtual weldment or part may be derived from acomputer-aided design (CAD) model, in accordance with an embodiment ofthe present invention. Therefore, testing and inspection may besimulated on irregular geometries for specific parts. In accordance withan embodiment of the present application, the VRAW system is alsocapable of performing virtual inspection of a predefined virtualweldment. For example, the VRAW system may include pre-made virtualweldments which a student may refer to in order to learn how a good weldshould look.

Various types of welding discontinuities and defects include improperweld size, poor bead placement, concave bead, excessive convexity,undercut, porosity, incomplete fusion, slag inclusion, excess spatter,overfill, cracks, and burnthrough or melt through which are all wellknown in the art. For example, undercut is often due to an incorrectangle of welding. Porosity is cavity type discontinuities formed by gasentrapment during solidification, often caused by moving the arc too faraway from the weldment. Other problems may occur due to an incorrectprocess, fill material, wire size, or technique, all of which may besimulated.

Various types of destructive tests that may be performed include a rootbend test, a face bend test, a side bend test, a tensile or pull test, abreak test (e.g., a nick break test or a T-joint break test), an impacttest, and a hardness test which are all well known in the art. For manyof these tests, a piece is cut out of the weldment and the test isperformed on that piece. For example, a root bend test is a test thatbends the cut piece from the weldment such that the weld root is on theconvex surface of a specified bend radius. A side bend test is a testthat bends the weldment such that the side of a transverse section ofthe weld is on the convex surface of a specified bend radius. A facebend test is a test that bends the weldment such that the weld face ison the convex surface of a specified bend radius.

A further destructive test is a tensile or pull test where a cut piecefrom a weldment is pulled or stretched until the weld breaks, testingthe elastic limit and tensile strength of the weld. Another destructivetest is a break test. One type of break test is a test on a weldmenthaving two sections welded together at 90 degrees to each other to forma T-joint, where one section is bent over toward the other section todetermine if the weld breaks or not. If the weld breaks, the internalweld bead can be inspected. An impact test is a test where an impactingelement is forced into a weldment at various temperatures to determinethe ability of the weldment to resist impact. A weldment may have goodstrength under static loading, yet may fracture if subjected to ahigh-velocity impact. For example, a pendulum device may be used toswing down and hit a weldment (possibly breaking the weldment) and iscalled a Charpy impact test.

A further destructive test is a hardness test which tests a weldmentsability to resist indentation or penetration at the weld joint. Thehardness of a weldment depends on the resultant metallurgical propertiesat the weld joint which is based, in part, on how the weld joint coolsin the heat-affected zone. Two types of hardness tests are the Brinelltest and the Rockwell tests. Both tests use a penetrator with either ahard sphere or a sharp diamond point. The penetrator is applied to theweld under a standardized load. When the load is removed, thepenetration is measured. The test may be performed at several points inthe surrounding metal and is a good indicator of potential cracking. Afurther type of destructive test is a bend-on-pipe test where a weldedpipe is cut to take a piece out of each of the four quadrants of thepipe. A root bend is performed on two of the pieces and a face bend isperformed on the other two pieces.

Various types of non-destructive tests that may be performed includeradiographic tests and ultrasonic tests. In a radiographic test, theweldment is exposed to X-rays and an X-ray image of the weld joint isgenerated which can be examined. In an ultrasonic test, the weldment isexposed to ultrasonic energy and various properties of the weld jointare derived from the reflected ultrasonic waves. For certain types ofnon-destructive testing, the weldment is subjected (in a virtual manner)to X-ray or ultrasound exposure and defects such as internal porosity,slag entrapment, and lack of penetration are visually presented to theuser. Another type of non-destructive testing is dye penetrant or liquidpenetrant testing which may be simulated in a virtual reality manner. Aweldment is subjected to a dye material and the weldment is then exposedto a developer to determine, for example, if surface cracks exist thatare not visible to the naked eye. A further non-destructive testing ismagnetic particle testing that is also used for detecting cracks and maybe simulated in a virtual reality manner. Small cracks below the surfaceof a weldment can be created by improper heat input to the weldment. Inaccordance with an embodiment of the present invention, travel speed andother welding process parameters are tracked in the virtual realityenvironment and used to determine heat input to the weldment and,therefore, cracks near the surface of the weldment which may be detectedusing virtual non-destructive testing.

Furthermore, simulation of a weldment in a simulated structure may beperformed. For example, a virtual weldment having a virtual weld jointcreated by a user of a VRAW system may be incorporated into a virtualsimulation of a bridge for testing. The virtual weldment may correspondto a key structural element of the bridge, for example. The bridge maybe specified to last one-hundred years before failing. The test mayinvolve observing the bridge over time (i.e., virtual time) to see ifthe weldment fails. For example, if the weldment is of poor quality(i.e., has unacceptable discontinuities or defects), the simulation mayshow an animation of the bridge collapsing after 45 years.

FIGS. 1-19C disclose an embodiment of a virtual reality arc welding(VRAW) system 100 capable of simulating, in virtual reality space, areal time welding scenario including formation of a virtual weldment bya user (welder) and various defect and discontinuity characteristicsassociated with the weldment, as well as simulating testing andinspection of the virtual weldment and displaying an animation of thevirtual weldment under test to observe the effects. The VRAW system iscapable of creating a sophisticated virtual rendering of a weldment andperforming a sophisticated analysis of the virtual rendering thatcompares various characteristics of the virtual weldment to a weldingcode.

Virtual inspection may be implemented on the VRAW system in any of anumber of different ways and/or combinations thereof. In accordance withone embodiment of the present invention, the VRAW system includes anexpert system and is driven by a set of rules. An expert system issoftware that attempts to provide an answer to a problem, or clarifyuncertainties where normally one or more human experts would need to beconsulted. Expert systems are most common in a specific problem domain,and is a traditional application and/or subfield of artificialintelligence. A wide variety of methods can be used to simulate theperformance of the expert, however, common to many are 1) the creationof a knowledge base which uses some knowledge representation formalismto capture the Subject Matter Expert's (SME) knowledge (e.g., acertified welding inspector's knowledge) and 2) a process of gatheringthat knowledge from the SME and codifying it according to the formalism,which is called knowledge engineering. Expert systems may or may nothave learning components but a third common element is that, once thesystem is developed, it is proven by being placed in the same real worldproblem solving situation as the human SME, typically as an aid to humanworkers or a supplement to some information system.

In accordance with another embodiment of the present invention, the VRAWsystem includes support vector machines. Support vector machines (SVMs)are a set of related supervised learning methods used for classificationand regression. Given a set of training examples, each marked asbelonging to one of two categories, a SVM training algorithm builds amodel that predicts whether a new example falls into one category or theother (e.g., pass/fail categories for particular defects anddiscontinuities). Intuitively, an SVM model is a representation of theexamples as points in space, mapped so that the examples of the separatecategories are divided by a clear gap that is as wide as possible. Newexamples are then mapped into that same space and predicted to belong toa category based on which side of the gap they fall on.

In accordance with still a further embodiment of the present invention,the VRAW system includes a neural network that is capable of beingtrained and adapted to new scenarios. A neural network is made up ofinterconnecting artificial neurons (programming constructs that mimicthe properties of biological neurons). Neural networks may either beused to gain an understanding of biological neural networks, or forsolving artificial intelligence problems without necessarily creating amodel of a real biological system. In accordance with an embodiment ofthe present invention, a neural network is devised that inputs defectand discontinuity data from virtual weldment data, and outputs pass/faildata.

In accordance with various embodiments of the present invention,intelligent agents may be employed to provide feedback to a studentconcerning areas where the student needs more practice, or to providefeedback to an instructor or educator as to how to modify the teachingcurriculum to improve student learning. In artificial intelligence, anintelligent agent is an autonomous entity, usually implemented insoftware, which observes and acts upon an environment and directs itsactivity towards achieving goals. An intelligent agent may be able tolearn and use knowledge to achieve a goal (e.g., the goal of providingrelevant feedback to a welding student or a welding educator).

In accordance with an embodiment of the present invention, a virtualrendering of a weldment created using the VRAW system is exported to adestructive/non-destructive testing portion of the system. The testingportion of the system is capable of automatically generating cutsections of the virtual weldment (for destructive testing) andsubmitting those cut sections to one of a plurality of possible testswithin the testing portion of the VRAW system. Each of the plurality oftests is capable of generating an animation illustrating that particulartest. The VRAW system is capable of displaying the animation of the testto the user. The animation clearly shows to the user whether or not thevirtual weldment generated by the user passes the test. Fornon-destructive testing, the weldment is subjected (in a virtual manner)to X-ray or ultrasound exposure and defects such as internal porosity,slag entrapment, and lack of penetration are visually presented to theuser.

For example, a virtual weldment that is subjected to a virtual bend testmay be shown to break in the animation at a location where a particulartype of defect occurs in the weld joint of the virtual weldment. Asanother example, a virtual weldment that is subjected to a virtual bendtest may be shown to bend in the animation and crack or show asignificant amount of defect, even though the weldment does notcompletely break. The same virtual weldment may be tested over and overagain for different tests using the same cut sections (e.g., the cutsections may be reconstituted or re-rendered by the VRAW system) ordifferent cut sections of the virtual weldment. In accordance with anembodiment of the present invention, a virtual weldment is tagged withmetallurgical characteristics such as, for example, type of metal andtensile strength which are factored into the particular selecteddestructive/non-destructive test. Various common base welding metals aresimulated, including welding metals such as aluminum and stainless, inaccordance with various embodiments of the present invention.

In accordance with an embodiment of the present invention, a backgroundrunning expert system may pop up in a window on a display of the VRAWsystem and indicate to the user (e.g., via a text message and/orgraphically) why the weldment failed the test (e.g., too much porosityat these particular points in the weld joint) and what particularwelding standard(s) was not met. In accordance with another embodimentof the present invention, the VRAW system may hyper-text link to anexternal tool that ties the present test to a particular weldingstandard. Furthermore, a user may have access to a knowledge baseincluding text, pictures, video, and diagrams to support their training.

In accordance with an embodiment of the present invention, the animationof a particular destructive/non-destructive test is a 3D rendering ofthe virtual weldment as modified by the test such that a user may movethe rendered virtual weldment around in a three-dimensional manner on adisplay of the VRAW system during the test to view the test from variousangles and perspectives. The same 3D rendered animation of a particulartest may be played over and over again to allow for maximum trainingbenefit for the same user or for multiple users.

In accordance with an embodiment of the present invention, the renderedvirtual weldment and/or the corresponding 3D rendered animation of thevirtual weldment under test may be exported to an inspection portion ofthe system to perform an inspection of the weld and/or to train a userin welding inspection (e.g., for becoming a certified weldinginspector). The inspection portion of the system includes a teachingmode and a training mode.

In the teaching mode, the virtual weldment and/or the 3D renderedanimation of a virtual weldment under test is displayed and viewed by agrader (trainer) along with a welding student. The trainer and thewelding student are able to view and interact with the virtual weldment.The trainer is able to make a determination (e.g., via a scoring method)how well the welding student performed at identifying defects anddiscontinuities in the virtual weldment, and indicate to the weldingstudent how well the welding student performed and what the studentmissed by interacting with the displayed virtual weldment (viewing fromdifferent perspectives, etc.).

In the training mode, the system asks a welding inspector studentvarious questions about the virtual weldment and allows the weldinginspector student to input answers to the questions. The system mayprovide the welding inspector student with a grade at the end of thequestioning. For example, the system may initially provide samplequestions to the welding inspector student for one virtual weldment andthen proceed to provide timed questions to the welding inspector studentfor another virtual weldment which is to be graded during a testingmode.

The inspection portion of the system may also provide certaininteractive tools that help a welding inspector student or trainer todetect defects and make certain measurements on the virtual weld whichare compared to predefined welding standards (e.g., a virtual gauge thatmeasures penetration of a root weld and compares the measurement to arequired standard penetration). Grading of a welding inspector studentmay also include whether or not the welding inspector student uses thecorrect interactive tools to evaluate the weld. In accordance with anembodiment of the present invention, the inspection portion of thesystem, based on grading (i.e., scoring) determines which areas thewelding inspector student needs help and provides the welding inspectorstudent with more representative samples upon which to practiceinspecting.

As discussed previously herein, intelligent agents may be employed toprovide feedback to a student concerning areas where the student needsmore practice, or to provide feedback to an instructor or educator as tohow to modify the teaching curriculum to improve student learning. Inartificial intelligence, an intelligent agent is an autonomous entity,usually implemented in software, which observes and acts upon anenvironment and directs its activity towards achieving goals. Anintelligent agent may be able to learn and use knowledge to achieve agoal (e.g., the goal of providing relevant feedback to a welding studentor a welding educator). In accordance with an embodiment of the presentinvention, the environment perceived and acted upon by an intelligentagent is the virtual reality environment generated by the VRAW system,for example.

Again, the various interactive inspection tools may be used on eitherthe virtual weldment before being subjected to testing, the virtualweldment after being subjected to testing, or both. The variousinteractive inspection tools and methodologies are configured forvarious welding processes, types of metals, and types of weldingstandards, in accordance with an embodiment of the present invention. Onthe standalone VWI system, the interactive inspection tools may bemanipulated using a keyboard and mouse, for example. On the VRAW system,the interactive inspection tools may be manipulated via a joystickand/or a console panel, for example.

The VRAW system comprises a programmable processor-based subsystem, aspatial tracker operatively connected to the programmableprocessor-based subsystem, at least one mock welding tool capable ofbeing spatially tracked by the spatial tracker, and at least one displaydevice operatively connected to the programmable processor-basedsubsystem. The system is capable of simulating, in a virtual realityspace, a weld puddle having real-time molten metal fluidity and heatdissipation characteristics. The system is also capable of displayingthe simulated weld puddle on the display device in real-time. Thereal-time molten metal fluidity and heat dissipation characteristics ofthe simulated weld puddle provide real-time visual feedback to a user ofthe mock welding tool when displayed, allowing the user to adjust ormaintain a welding technique in real-time in response to the real-timevisual feedback (i.e., helps the user learn to weld correctly). Thedisplayed weld puddle is representative of a weld puddle that would beformed in the real-world based on the user's welding technique and theselected welding process and parameters. By viewing a puddle (e.g.,shape, color, slag, size, stacked dimes), a user can modify histechnique to make a good weld and determine the type of welding beingdone. The shape of the puddle is responsive to the movement of the gunor stick. As used herein, the term “real-time” means perceiving andexperiencing in time in a simulated environment in the same way that auser would perceive and experience in a real-world welding scenario.Furthermore, the weld puddle is responsive to the effects of thephysical environment including gravity, allowing a user to realisticallypractice welding in various positions including overhead welding andvarious pipe welding angles (e.g., 1G, 2G, 5G, 6G). Such a real-timevirtual welding scenario results in the generating of datarepresentative of a virtual weldment.

FIG. 1 illustrates an example embodiment of a system block diagram of asystem 100 providing arc welding training in a real-time virtual realityenvironment. The system 100 includes a programmable processor-basedsubsystem (PPS) 110. The PPS 110 provides the hardware and softwareconfigured as a rendering engine for providing 3D animated renderings ofvirtual weldments. The PPS 110 also provides hardware and softwareconfigured as an analysis engine for performing testing and inspectionof a virtual weldment. In the context of the system of FIG. 1, a virtualweldment is the resultant simulation of a welding coupon that has gonethrough a simulated welding process to form a weld bead or weld joint.

The system 100 further includes a spatial tracker (ST) 120 operativelyconnected to the PPS 110. The system 100 also includes a physicalwelding user interface (WUI) 130 operatively connected to the PPS 110and a face-mounted display device (FMDD) 140 (see FIGS. 9A-9C)operatively connected to the PPS 110 and the ST 120. However, certainembodiments may not provide a FMDD. The system 100 further includes anobserver display device (ODD) 150 operatively connected to the PPS 110.The system 100 also includes at least one mock welding tool (MWT) 160operatively connected to the ST 120 and the PPS 110. The system 100further includes a table/stand (T/S) 170 and at least one welding coupon(WC) 180 capable of being attached to the T/S 170. In accordance with analternative embodiment of the present invention, a mock gas bottle isprovided (not shown) simulating a source of shielding gas and having anadjustable flow regulator.

FIG. 2 illustrates an example embodiment of a combined simulated weldingconsole 135 (simulating a welding power source user interface) andobserver display device (ODD) 150 of the system 100 of FIG. 1. Thephysical WUI 130 resides on a front portion of the console 135 andprovides knobs, buttons, and a joystick for user selection of variousmodes and functions. The ODD 150 is attached to a top portion of theconsole 135, in accordance with an embodiment of the present invention.The MWT 160 rests in a holder attached to a side portion of the console135. Internally, the console 135 holds the PPS 110 and a portion of theST 120.

FIG. 3 illustrates an example embodiment of the observer display device(ODD) 150 of FIG. 2. In accordance with an embodiment of the presentinvention, the ODD 150 is a liquid crystal display (LCD) device. Otherdisplay devices are possible as well. For example, the ODD 150 may be atouchscreen display, in accordance with another embodiment of thepresent invention. The ODD 150 receives video (e.g., SVGA format) anddisplay information from the PPS 110.

As shown in FIG. 3, the ODD 150 is capable of displaying a first userscene showing various welding parameters 151 including position, tip towork, weld angle, travel angle, and travel speed. These parameters maybe selected and displayed in real time in graphical form and are used toteach proper welding technique. Furthermore, as shown in FIG. 3, the ODD150 is capable of displaying simulated welding discontinuity states 152including, for example, improper weld size, poor bead placement, concavebead, excessive convexity, undercut, porosity, incomplete fusion, slaginclusion, excess spatter, overfill, and burnthrough (melt through).Undercut is a groove melted into the base metal adjacent to the weld orweld root and left unfilled by weld metal. Undercut is often due to anincorrect angle of welding. Porosity is cavity type discontinuitiesformed by gas entrapment during solidification often caused by movingthe arc too far away from the coupon. Such simulated weldingdiscontinuity states are generated by the system 100 during a simulatedwelding process to form a virtual weldment using a simulated weldingcoupon.

Also, as shown in FIG. 3, the ODD 150 is capable of displaying userselections 153 including menu, actions, visual cues, new coupon, and endpass. These user selections are tied to user buttons on the console 135.As a user makes various selections via, for example, a touchscreen ofthe ODD 150 or via the physical WUI 130, the displayed characteristicscan change to provide selected information and other options to theuser. Furthermore, the ODD 150 may display a view seen by a welderwearing the FMDD 140 at the same angular view of the welder or atvarious different angles, for example, chosen by an instructor. The ODD150 may be viewed by an instructor and/or students for various trainingpurposes, including for destructive/non-destructive testing andinspection of a virtual weldment. For example, the view may be rotatedaround the finished weld allowing visual inspection by an instructor. Inaccordance with an alternate embodiment of the present invention, videofrom the system 100 may be sent to a remote location via, for example,the Internet for remote viewing and/or critiquing. Furthermore, audiomay be provided, allowing real-time audio communication between astudent and a remote instructor.

FIG. 4 illustrates an example embodiment of a front portion of thesimulated welding console 135 of FIG. 2 showing a physical welding userinterface (WUI) 130. The WUI 130 includes a set of buttons 131corresponding to the user selections 153 displayed on the ODD 150. Thebuttons 131 are colored to correspond to the colors of the userselections 153 displayed on the ODD 150. When one of the buttons 131 ispressed, a signal is sent to the PPS 110 to activate the correspondingfunction. The WUI 130 also includes a joystick 132 capable of being usedby a user to select various parameters and selections displayed on theODD 150. The WUI 130 further includes a dial or knob 133 for adjustingwire feed speed/amps, and another dial or knob 134 for adjustingvolts/trim. The WUI 130 also includes a dial or knob 136 for selectingan arc welding process. In accordance with an embodiment of the presentinvention, three arc welding processes are selectable including fluxcored arc welding (FCAW) including gas-shielded and self-shieldedprocesses; gas metal arc welding (GMAW) including short arc, axialspray, STT, and pulse; gas tungsten arc welding (GTAW); and shieldedmetal arc welding (SMAW) including E6010, E6013, and E7018 electrodes.The WUI 130 further includes a dial or knob 137 for selecting a weldingpolarity. In accordance with an embodiment of the present invention,three arc welding polarities are selectable including alternatingcurrent (AC), positive direct current (DC+), and negative direct current(DC−).

FIG. 5 illustrates an example embodiment of a mock welding tool (MWT)160 of the system 100 of FIG. 1. The MWT 160 of FIG. 5 simulates a stickwelding tool for plate and pipe welding and includes a holder 161 and asimulated stick electrode 162. A trigger on the MWD 160 is used tocommunicate a signal to the PPS 110 to activate a selected simulatedwelding process. The simulated stick electrode 162 includes a tactilelyresistive tip 163 to simulate resistive feedback that occurs during, forexample, a root pass welding procedure in real-world pipe welding orwhen welding a plate. If the user moves the simulated stick electrode162 too far back out of the root, the user will be able to feel or sensethe lower resistance, thereby deriving feedback for use in adjusting ormaintaining the current welding process.

It is contemplated that the stick welding tool may incorporate anactuator, not shown, that withdraws the simulated stick electrode 162during the virtual welding process. That is to say that as a userengages in virtual welding activity, the distance between holder 161 andthe tip of the simulated stick electrode 162 is reduced to simulateconsumption of the electrode. The consumption rate, i.e. withdrawal ofthe stick electrode 162, may be controlled by the PPS 110 and morespecifically by coded instructions executed by the PPS 110. Thesimulated consumption rate may also depend on the user's technique. Itis noteworthy to mention here that as the system 100 facilitates virtualwelding with different types of electrodes, the consumption rate orreduction of the stick electrode 162 may change with the weldingprocedure used and/or setup of the system 100.

Other mock welding tools are possible as well, in accordance with otherembodiments of the present invention, including a MWD that simulates ahand-held semi-automatic welding gun having a wire electrode fed throughthe gun, for example. Furthermore, in accordance with other certainembodiments of the present invention, a real welding tool could be usedas the MWT 160 to better simulate the actual feel of the tool in theuser's hands, even though, in the system 100, the tool would not be usedto actually create a real arc. Also, a simulated grinding tool may beprovided, for use in a simulated grinding mode of the simulator 100.Similarly, a simulated cutting tool may be provided, for use in asimulated cutting mode of the simulator 100 such as, for example, asused in Oxyfuel and plasma cutting. Furthermore, a simulated gastungsten arc welding (GTAW) torch or filler material may be provided foruse in the simulator 100.

FIG. 6 illustrates an example embodiment of a table/stand (T/S) 170 ofthe system 100 of FIG. 1. The T/S 170 includes an adjustable table 171,a stand or base 172, an adjustable arm 173, and a vertical post 174. Thetable 171, the stand 172, and the arm 173 are each attached to thevertical post 174. The table 171 and the arm 173 are each capable ofbeing manually adjusted upward, downward, and rotationally with respectto the vertical post 174. The arm 173 is used to hold various weldingcoupons (e.g., welding coupon 175) and a user may rest his/her arm onthe table 171 when training. The vertical post 174 is indexed withposition information such that a user may know exactly where the arm 173and the table 171 are vertically positioned on the post 171. Thisvertical position information may be entered into the system by a userusing the WUI 130 and the ODD 150.

In accordance with an alternative embodiment of the present invention,the positions of the table 171 and the arm 173 may be automatically setby the PSS 110 via preprogrammed settings, or via the WUI 130 and/or theODD 150 as commanded by a user. In such an alternative embodiment, theT/S 170 includes, for example, motors and/or servo-mechanisms, andsignal commands from the PPS 110 activate the motors and/orservo-mechanisms. In accordance with a further alternative embodiment ofthe present invention, the positions of the table 171 and the arm 173and the type of coupon are detected by the system 100. In this way, auser does not have to manually input the position information via theuser interface. In such an alternative embodiment, the T/S 170 includesposition and orientation detectors and sends signal commands to the PPS110 to provide position and orientation information, and the WC 175includes position detecting sensors (e.g., coiled sensors for detectingmagnetic fields). A user is able to see a rendering of the T/S 170adjust on the ODD 150 as the adjustment parameters are changed, inaccordance with an embodiment of the present invention.

FIG. 7A illustrates an example embodiment of a pipe welding coupon (WC)175 of the system 100 of FIG. 1. The WC 175 simulates two six inchdiameter pipes 175′ and 175″ placed together to form a root 176 to bewelded. The WC 175 includes a connection portion 177 at one end of theWC 175, allowing the WC 175 to be attached in a precise and repeatablemanner to the arm 173. FIG. 7B illustrates the pipe WC 175 of FIG. 7Amounted on the arm 173 of the table/stand (TS) 170 of FIG. 6. Theprecise and repeatable manner in which the WC 175 is capable of beingattached to the arm 173 allows for spatial calibration of the WC 175 tobe performed only once at the factory. Then, in the field, as long asthe system 100 is told the position of the arm 173, the system 100 isable to track the MWT 160 and the FMDD 140 with respect to the WC 175 ina virtual environment. A first portion of the arm 173, to which the WC175 is attached, is capable of being tilted with respect to a secondportion of the arm 173, as shown in FIG. 6. This allows the user topractice pipe welding with the pipe in any of several differentorientations and angles.

FIG. 8 illustrates various elements of an example embodiment of thespatial tracker (ST) 120 of FIG. 1. The ST 120 is a magnetic trackerthat is capable of operatively interfacing with the PPS 110 of thesystem 100. The ST 120 includes a magnetic source 121 and source cable,at least one sensor 122 and associated cable, host software on disk 123,a power source 124 and associated cable, USB and RS-232 cables 125, anda processor tracking unit 126. The magnetic source 121 is capable ofbeing operatively connected to the processor tracking unit 126 via acable. The sensor 122 is capable of being operatively connected to theprocessor tracking unit 126 via a cable. The power source 124 is capableof being operatively connected to the processor tracking unit 126 via acable. The processor tracking unit 126 is cable of being operativelyconnected to the PPS 110 via a USB or RS-232 cable 125. The hostsoftware on disk 123 is capable of being loaded onto the PPS 110 andallows functional communication between the ST 120 and the PPS 110.

Referring to FIG. 6 and FIG. 8, the magnetic source 121 of the ST 120 ismounted on the first portion of the arm 173. The magnetic source 121creates a magnetic field around the source 121, including the spaceencompassing the WC 175 attached to the arm 173, which establishes a 3Dspatial frame of reference. The T/S 170 is largely non-metallic(non-ferric and non-conductive) so as not to distort the magnetic fieldcreated by the magnetic source 121. The sensor 122 includes threeinduction coils orthogonally aligned along three spatial directions. Theinduction coils of the sensor 122 each measure the strength of themagnetic field in each of the three directions and provide thatinformation to the processor tracking unit 126. As a result, the system100 is able to know where any portion of the WC 175 is with respect tothe 3D spatial frame of reference established by the magnetic field whenthe WC 175 is mounted on the arm 173. The sensor 122 may be attached tothe MWT 160 or to the FMDD 140, allowing the MWT 160 or the FMDD 140 tobe tracked by the ST 120 with respect to the 3D spatial frame ofreference in both space and orientation. When two sensors 122 areprovided and operatively connected to the processor tracking unit 126,both the MWT 160 and the FMDD 140 may be tracked. In this manner, thesystem 100 is capable of creating a virtual WC, a virtual MWT, and avirtual T/S in virtual reality space and displaying the virtual WC, thevirtual MWT, and the virtual T/S on the FMDD 140 and/or the ODD 150 asthe MWT 160 and the FMDD 140 are tracked with respect to the 3D spatialframe of reference.

In accordance with an alternative embodiment of the present invention,the sensor(s) 122 may wirelessly interface to the processor trackingunit 126, and the processor tracking unit 126 may wirelessly interfaceto the PPS 110. In accordance with other alternative embodiments of thepresent invention, other types of spatial trackers 120 may be used inthe system 100 including, for example, an accelerometer/gyroscope-basedtracker, an optical tracker (active or passive), an infrared tracker, anacoustic tracker, a laser tracker, a radio frequency tracker, aninertial tracker, and augmented reality based tracking systems. Othertypes of trackers may be possible as well.

FIG. 9A illustrates an example embodiment of the face-mounted displaydevice 140 (FMDD) of the system 100 of FIG. 1. FIG. 9B is anillustration of how the FMDD 140 of FIG. 9A is secured on the head of auser. FIG. 9C illustrates an example embodiment of the FMDD 140 of FIG.9A integrated into a welding helmet 900. The FMDD 140 operativelyconnects to the PPS 110 and the ST 120 either via wired means orwirelessly. A sensor 122 of the ST 120 may be attached to the FMDD 140or to the welding helmet 900, in accordance with various embodiments ofthe present invention, allowing the FMDD 140 and/or welding helmet 900to be tracked with respect to the 3D spatial frame of reference createdby the ST 120.

In accordance with an embodiment of the present invention, the FMDD 140includes two high-contrast SVGA 3D OLED microdisplays capable ofdelivering fluid full-motion video in the 2D and frame sequential videomodes. Video of the virtual reality environment is provided anddisplayed on the FMDD 140. A zoom (e.g., 2×) mode may be provided,allowing a user to simulate a cheater lens, for example.

The FMDD 140 further includes two earbud speakers 910, allowing the userto hear simulated welding-related and environmental sounds produced bythe system 100. The FMDD 140 may operatively interface to the PPS 110via wired or wireless means, in accordance with various embodiments ofthe present invention. In accordance with an embodiment of the presentinvention, the PPS 110 provides stereoscopic video to the FMDD 140,providing enhanced depth perception to the user. In accordance with analternate embodiment of the present invention, a user is able to use acontrol on the MWT 160 (e.g., a button or switch) to call up and selectmenus and display options on the FMDD 140. This may allow the user toeasily reset a weld if he makes a mistake, change certain parameters, orback up a little to re-do a portion of a weld bead trajectory, forexample.

FIG. 10 illustrates an example embodiment of a subsystem block diagramof the programmable processor-based subsystem (PPS) 110 of the system100 of FIG. 1. The PPS 110 includes a central processing unit (CPU) 111and two graphics processing units (GPU) 115, in accordance with anembodiment of the present invention. The two GPUs 115 are programmed toprovide virtual reality simulation of a weld puddle (a.k.a. a weld pool)having real-time molten metal fluidity and heat absorption anddissipation characteristics, in accordance with an embodiment of thepresent invention.

FIG. 11 illustrates an example embodiment of a block diagram of agraphics processing unit (GPU) 115 of the PPS 110 of FIG. 10. Each GPU115 supports the implementation of data parallel algorithms. Inaccordance with an embodiment of the present invention, each GPU 115provides two video outputs 118 and 119 capable of providing two virtualreality views. Two of the video outputs may be routed to the FMDD 140,rendering the welder's point of view, and a third video output may berouted to the ODD 150, for example, rendering either the welder's pointof view or some other point of view. The remaining fourth video outputmay be routed to a projector, for example. Both GPUs 115 perform thesame welding physics computations but may render the virtual realityenvironment from the same or different points of view. The GPU 115includes a compute unified device architecture (CUDA) 116 and a shader117. The CUDA 116 is the computing engine of the GPU 115 which isaccessible to software developers through industry standard programminglanguages. The CUDA 116 includes parallel cores and is used to run thephysics model of the weld puddle simulation described herein. The CPU111 provides real-time welding input data to the CUDA 116 on the GPU115. The shader 117 is responsible for drawing and applying all of thevisuals of the simulation. Bead and puddle visuals are driven by thestate of a wexel displacement map which is described later herein. Inaccordance with an embodiment of the present invention, the physicsmodel runs and updates at a rate of about 30 times per second. Duringvirtual destructive/non-destructive testing and inspection simulations,the GPUs 115 act as a rendering engine to provide 3D animated renderingsof a virtual weldment created during a simulated welding process.Furthermore, the CPU 111 acts as an analysis engine to provide testinganalysis of the virtual weldment with respect to the various defects anddiscontinuities that may be present in the virtual weldment.

FIG. 12 illustrates an example embodiment of a functional block diagramof the system 100 of FIG. 1. The various functional blocks of the system100 as shown in FIG. 12 are implemented largely via softwareinstructions and modules running on the PPS 110. The various functionalblocks of the system 100 include a physical interface 1201, torch andclamp models 1202, environment models 1203, sound content functionality1204, welding sounds 1205, stand/table model 1206, internal architecturefunctionality 1207, calibration functionality 1208, coupon models 1210,welding physics 1211, internal physics adjustment tool (tweaker) 1212,graphical user interface functionality 1213, graphing functionality1214, student reports functionality 1215, renderer 1216, bead rendering1217, 3D textures 1218, visual cues functionality 1219, scoring andtolerance functionality 1220, tolerance editor 1221, and special effects1222. The renderer 1216, the bead rendering 1217, the 3D textures 1218,and the scoring and tolerance functionality 1220 are employed duringvirtual destructive/non-destructive testing and inspection as well asduring a simulated welding process, in accordance with an embodiment ofthe present invention.

The internal architecture functionality 1207 provides the higher levelsoftware logistics of the processes of the system 100 including, forexample, loading files, holding information, managing threads, turningthe physics model on, and triggering menus. The internal architecturefunctionality 1207 runs on the CPU 111, in accordance with an embodimentof the present invention. Certain real-time inputs to the PPS 110include arc location, gun position, FMDD or helmet position, gun on/offstate, and contact made state (yes/no).

The graphical user interface functionality 1213 allows a user, throughthe ODD 150 using the joystick 132 of the physical user interface 130,to set up a welding scenario, a testing scenario, or an inspectionscenario. In accordance with an embodiment of the present invention, theset up of a welding scenario includes selecting a language, entering auser name, selecting a practice plate (i.e., a welding coupon),selecting a welding process (e.g., FCAW, GMAW, SMAW) and associatedaxial spray, pulse, or short arc methods, selecting a gas type and flowrate, selecting a type of stick electrode (e.g., 6010 or 7018), andselecting a type of flux cored wire (e.g., self-shielded, gas-shielded).The set up of a welding scenario also includes selecting a table height,an arm height, an arm position, and an arm rotation of the T/S 170. Theset up of a welding scenario further includes selecting an environment(e.g., a background environment in virtual reality space), setting awire feed speed, setting a voltage level, setting an amperage, selectinga polarity, and turning particular visual cues on or off. Similarly, theset up of a virtual testing or inspection scenario may include selectinga language, entering a user name, selecting a virtual weldment,selecting a destructive or a non-destructive test, selecting aninteractive tool, and selecting an animated perspective view.

During a simulated welding scenario, the graphing functionality 1214gathers user performance parameters and provides the user performanceparameters to the graphical user interface functionality 1213 fordisplay in a graphical format (e.g., on the ODD 150). Trackinginformation from the ST 120 feeds into the graphing functionality 1214.The graphing functionality 1214 includes a simple analysis module (SAM)and a whip/weave analysis module (WWAM). The SAM analyzes user weldingparameters including welding travel angle, travel speed, weld angle,position, and tip to work distance by comparing the welding parametersto data stored in bead tables. The WWAM analyzes user whippingparameters including dime spacing, whip time, and puddle time. The WWAMalso analyzes user weaving parameters including width of weave, weavespacing, and weave timing. The SAM and WWAM interpret raw input data(e.g., position and orientation data) into functionally usable data forgraphing. For each parameter analyzed by the SAM and the WWAM, atolerance window is defined by parameter limits around an optimum orideal set point input into bead tables using the tolerance editor 1221,and scoring and tolerance functionality 1220 is performed.

The tolerance editor 1221 includes a weldometer which approximatesmaterial usage, electrical usage, and welding time. Furthermore, whencertain parameters are out of tolerance, welding discontinuities (i.e.,welding defects) may occur. The state of any welding discontinuities areprocessed by the graphing functionality 1214 and presented via thegraphical user interface functionality 1213 in a graphical format. Suchwelding discontinuities include improper weld size, poor bead placement,concave bead, excessive convexity, undercut, porosity, incompletefusion, slag entrapment, overfill, burnthrough, and excessive spatter.In accordance with an embodiment of the present invention, the level oramount of a discontinuity is dependent on how far away a particular userparameter is from the optimum or ideal set point. Such weldingdiscontinuities that are generated as part of the simulated weldingprocess are used as inputs to the virtual destructive/non-destructiveand inspection processes as associated with a virtual weldment.

Different parameter limits may be pre-defined for different types ofusers such as, for example, welding novices, welding experts, andpersons at a trade show. The scoring and tolerance functionality 1220provide number scores depending on how close to optimum (ideal) a useris for a particular parameter and depending on the level ofdiscontinuities or defects present in the weld. The optimum values arederived from real-world data. Information from the scoring and tolerancefunctionality 1220 and from the graphics functionality 1214 may be usedby the student reports functionality 1215 to create a performance reportfor an instructor and/or a student.

The system 100 is capable of analyzing and displaying the results ofvirtual welding activity. By analyzing the results, it is meant thatsystem 100 is capable of determining when during the welding pass andwhere along the weld joints, the user deviated from the acceptablelimits of the welding process. A score may be attributed to the user'sperformance. In one embodiment, the score may be a function of deviationin position, orientation and speed of the mock welding tool 160 throughranges of tolerances, which may extend from an ideal welding pass tomarginal or unacceptable welding activity. Any gradient of ranges may beincorporated into the system 100 as chosen for scoring the user'sperformance. Scoring may be displayed numerically or alpha-numerically.Additionally, the user's performance may be displayed graphicallyshowing, in time and/or position along the weld joint, how closely themock welding tool traversed the weld joint. Parameters such as travelangle, work angle, speed, and distance from the weld joint are examplesof what may be measured, although any parameters may be analyzed forscoring purposes. The tolerance ranges of the parameters are taken fromreal-world welding data, thereby providing accurate feedback as to howthe user will perform in the real world. In another embodiment, analysisof the defects corresponding to the user's performance may also beincorporated and displayed on the ODD 150. In this embodiment, a graphmay be depicted indicating what type of discontinuity resulted frommeasuring the various parameters monitored during the virtual weldingactivity. While occlusions may not be visible on the ODD 150, defectsmay still have occurred as a result of the user's performance, theresults of which may still be correspondingly displayed, i.e. graphed,and also tested (e.g., via a bend test) and inspected.

Visual cues functionality 1219 provide immediate feedback to the user bydisplaying overlaid colors and indicators on the FMDD 140 and/or the ODD150. Visual cues are provided for each of the welding parameters 151including position, tip to work distance, weld angle, travel angle,travel speed, and arc length (e.g., for stick welding) and visuallyindicate to the user if some aspect of the user's welding techniqueshould be adjusted based on the predefined limits or tolerances. Visualcues may also be provided for whip/weave technique and weld bead “dime”spacing, for example. Visual cues may be set independently or in anydesired combination.

Calibration functionality 1208 provides the capability to match upphysical components in real world space (3D frame of reference) withvisual components in virtual reality space. Each different type ofwelding coupon (WC) is calibrated in the factory by mounting the WC tothe arm 173 of the T/S 170 and touching the WC at predefined points(indicated by, for example, three dimples on the WC) with a calibrationstylus operatively connected to the ST 120. The ST 120 reads themagnetic field intensities at the predefined points, provides positioninformation to the PPS 110, and the PPS 110 uses the positioninformation to perform the calibration (i.e., the translation from realworld space to virtual reality space).

Any particular type of WC fits into the arm 173 of the T/S 170 in thesame repeatable way to within very tight tolerances. Therefore, once aparticular WC type is calibrated, that WC type does not have to bere-calibrated (i.e., calibration of a particular type of WC is aone-time event). WCs of the same type are interchangeable. Calibrationensures that physical feedback perceived by the user during a weldingprocess matches up with what is displayed to the user in virtual realityspace, making the simulation seem more real. For example, if the userslides the tip of a MWT 160 around the corner of a actual WC 180, theuser will see the tip sliding around the corner of the virtual WC on theFMDD 140 as the user feels the tip sliding around the actual corner. Inaccordance with an embodiment of the present invention, the MWT 160 isplaced in a pre-positioned jig and is calibrated as well, based on theknown jig position.

In accordance with an alternative embodiment of the present invention,“smart” coupons are provided, having sensors on, for example, thecorners of the coupons. The ST 120 is able to track the corners of a“smart” coupon such that the system 100 continuously knows where the“smart” coupon is in real world 3D space. In accordance with a furtheralternative embodiment of the present invention, licensing keys areprovided to “unlock” welding coupons. When a particular WC is purchased,a licensing key is provided allowing the user to enter the licensing keyinto the system 100, unlocking the software associated with that WC. Inaccordance with another embodiment of the present invention, specialnon-standard welding coupons may be provided based on real-world CADdrawings of parts. Users may be able to train on welding a CAD part evenbefore the part is actually produced in the real world.

Sound content functionality 1204 and welding sounds 1205 provideparticular types of welding sounds that change depending on if certainwelding parameters are within tolerance or out of tolerance. Sounds aretailored to the various welding processes and parameters. For example,in a MIG spray arc welding process, a crackling sound is provided whenthe user does not have the MWT 160 positioned correctly, and a hissingsound is provided when the MWT 160 is positioned correctly. In a shortarc welding process, a steady crackling or frying sound is provided forproper welding technique, and a hissing sound may be provided whenundercutting is occurring. These sounds mimic real world soundscorresponding to correct and incorrect welding technique.

High fidelity sound content may be taken from real world recordings ofactual welding using a variety of electronic and mechanical means, inaccordance with various embodiments of the present invention. Inaccordance with an embodiment of the present invention, the perceivedvolume and directionality of sound is modified depending on theposition, orientation, and distance of the user's head (assuming theuser is wearing a FMDD 140 that is tracked by the ST 120) with respectto the simulated arc between the MWT 160 and the WC 180. Sound may beprovided to the user via ear bud speakers 910 in the FMDD 140 or viaspeakers configured in the console 135 or T/S 170, for example.

Environment models 1203 are provided to provide various backgroundscenes (still and moving) in virtual reality space. Such backgroundenvironments may include, for example, an indoor welding shop, anoutdoor race track, a garage, etc. and may include moving cars, people,birds, clouds, and various environmental sounds. The backgroundenvironment may be interactive, in accordance with an embodiment of thepresent invention. For example, a user may have to survey a backgroundarea, before starting welding, to ensure that the environment isappropriate (e.g., safe) for welding. Torch and clamp models 1202 areprovided which model various MWTs 160 including, for example, guns,holders with stick electrodes, etc. in virtual reality space.

Coupon models 1210 are provided which model various WCs 180 including,for example, flat plate coupons, T-joint coupons, butt-joint coupons,groove-weld coupons, and pipe coupons (e.g., 2-inch diameter pipe and6-inch diameter pipe) in virtual reality space. A stand/table model 1206is provided which models the various parts of the T/S 170 including anadjustable table 171, a stand 172, an adjustable arm 173, and a verticalpost 174 in virtual reality space. A physical interface model 1201 isprovided which models the various parts of the welding user interface130, console 135, and ODD 150 in virtual reality space. Again, theresultant simulation of a welding coupon that has gone through asimulated welding process to form a weld bead, a weld joint, apipe-on-plate weld, a plug weld, or a lap weld is known herein as avirtual weldment with respect to the system 100. Welding coupons may beprovided to support each of these scenarios.

In accordance with an embodiment of the present invention, simulation ofa weld puddle or pool in virtual reality space is accomplished where thesimulated weld puddle has real-time molten metal fluidity and heatdissipation characteristics. At the heart of the weld puddle simulationis the welding physics functionality 1211 (a.k.a., the physics model)which is run on the GPUs 115, in accordance with an embodiment of thepresent invention. The welding physics functionality employs a doubledisplacement layer technique to accurately model dynamicfluidity/viscosity, solidity, heat gradient (heat absorption anddissipation), puddle wake, and bead shape, and is described in moredetail herein with respect to FIGS. 14A-14C.

The welding physics functionality 1211 communicates with the beadrendering functionality 1217 to render a weld bead in all states fromthe heated molten state to the cooled solidified state. The beadrendering functionality 1217 uses information from the welding physicsfunctionality 1211 (e.g., heat, fluidity, displacement, dime spacing) toaccurately and realistically render a weld bead in virtual reality spacein real-time. The 3D textures functionality 1218 provides texture mapsto the bead rendering functionality 1217 to overlay additional textures(e.g., scorching, slag, grain) onto the simulated weld bead. Forexample, slag may be shown rendered over a weld bead during and justafter a welding process, and then removed to reveal the underlying weldbead. The renderer functionality 1216 is used to render variousnon-puddle specific characteristics using information from the specialeffects module 1222 including sparks, spatter, smoke, arc glow, fumesand gases, and certain discontinuities such as, for example, undercutand porosity.

The internal physics adjustment tool 1212 is a tweaking tool that allowsvarious welding physics parameters to be defined, updated, and modifiedfor the various welding processes. In accordance with an embodiment ofthe present invention, the internal physics adjustment tool 1212 runs onthe CPU 111 and the adjusted or updated parameters are downloaded to theGPUs 115. The types of parameters that may be adjusted via the internalphysics adjustment tool 1212 include parameters related to weldingcoupons, process parameters that allow a process to be changed withouthaving to reset a welding coupon (allows for doing a second pass),various global parameters that can be changed without resetting theentire simulation, and other various parameters.

FIG. 13 is a flow chart of an embodiment of a method 1300 of trainingusing the virtual reality training system 100 of FIG. 1. The methodproceeds as follows: in step 1310, move a mock welding tool with respectto a welding coupon in accordance with a welding technique; in step1320, track position and orientation of the mock welding tool inthree-dimensional space using a virtual reality system; in step 1330,view a display of the virtual reality welding system showing a real-timevirtual reality simulation of the mock welding tool and the weldingcoupon in a virtual reality space as the simulated mock welding tooldeposits a simulated weld bead material onto at least one simulatedsurface of the simulated welding coupon by forming a simulated weldpuddle in the vicinity of a simulated arc emitting from said simulatedmock welding tool; in step 1340, view on the display, real-time moltenmetal fluidity and heat dissipation characteristics of the simulatedweld puddle; in step 1350, modify in real-time, at least one aspect ofthe welding technique in response to viewing the real-time molten metalfluidity and heat dissipation characteristics of the simulated weldpuddle.

The method 1300 illustrates how a user is able to view a weld puddle invirtual reality space and modify his welding technique in response toviewing various characteristics of the simulated weld puddle, includingreal-time molten metal fluidity (e.g., viscosity) and heat dissipation.The user may also view and respond to other characteristics includingreal-time puddle wake and dime spacing. Viewing and responding tocharacteristics of the weld puddle is how most welding operations areactually performed in the real world. The double displacement layermodeling of the welding physics functionality 1211 run on the GPUs 115allows for such real-time molten metal fluidity and heat dissipationcharacteristics to be accurately modeled and represented to the user.For example, heat dissipation determines solidification time (i.e., howmuch time it takes for a wexel to completely solidify).

Furthermore, a user may make a second pass over the weld bead materialof the virtual weldment using the same or a different (e.g., a second)mock welding tool and/or welding process. In such a second passscenario, the simulation shows the simulated mock welding tool, thewelding coupon, and the original simulated weld bead material in virtualreality space as the simulated mock welding tool deposits a secondsimulated weld bead material merging with the first simulated weld beadmaterial by forming a second simulated weld puddle in the vicinity of asimulated arc emitting from the simulated mock welding tool. Additionalsubsequent passes using the same or different welding tools or processesmay be made in a similar manner. In any second or subsequent pass, theprevious weld bead material is merged with the new weld bead materialbeing deposited as a new weld puddle is formed in virtual reality spacefrom the combination of any of the previous weld bead material, the newweld bead material, and possibly the underlying coupon material thusmodifying the resultant virtual weldment, in accordance with certainembodiments of the present invention. Such subsequent passes may beneeded to make a large fillet or groove weld, performed to repair a weldbead formed by a previous pass, for example, or may include a hot passand one or more fill and cap passes after a root pass as is done in pipewelding. In accordance with various embodiments of the presentinvention, weld bead and base material may include mild steel, stainlesssteel, aluminum, nickel based alloys, or other materials.

FIGS. 14A-14B illustrate the concept of a welding element (wexel)displacement map 1420, in accordance with an embodiment of the presentinvention. FIG. 14A shows a side view of a flat welding coupon (WC) 1400having a flat top surface 1410. The welding coupon 1400 exists in thereal world as, for example, a plastic part, and also exists in virtualreality space as a simulated welding coupon. FIG. 14B shows arepresentation of the top surface 1410 of the simulated WC 1400 brokenup into a grid or array of welding elements (i.e., wexels) forming awexel map 1420. Each wexel (e.g., wexel 1421) defines a small portion ofthe surface 1410 of the welding coupon. The wexel map defines thesurface resolution. Changeable channel parameter values are assigned toeach wexel, allowing values of each wexel to dynamically change inreal-time in virtual reality weld space during a simulated weldingprocess. The changeable channel parameter values correspond to thechannels Puddle (molten metal fluidity/viscosity displacement), Heat(heat absorption/dissipation), Displacement (solid displacement), andExtra (various extra states, e.g., slag, grain, scorching, virginmetal). These changeable channels are referred to herein as PHED forPuddle, Heat, Extra, and Displacement, respectively.

FIG. 15 illustrates an example embodiment of a coupon space and a weldspace of the flat welding coupon (WC) 1400 of FIG. 14 simulated in thesystem 100 of FIG. 1. Points O, X, Y, and Z define the local 3D couponspace. In general, each coupon type defines the mapping from 3D couponspace to 2D virtual reality weld space. The wexel map 1420 of FIG. 14 isa two-dimensional array of values that map to weld space in virtualreality. A user is to weld from point B to point E as shown in FIG. 15.A trajectory line from point B to point E is shown in both 3D couponspace and 2D weld space in FIG. 15.

Each type of coupon defines the direction of displacement for eachlocation in the wexel map. For the flat welding coupon of FIG. 15, thedirection of displacement is the same at all locations in the wexel map(i.e., in the Z-direction). The texture coordinates of the wexel map areshown as S, T (sometimes called U, V) in both 3D coupon space and 2Dweld space, in order to clarify the mapping. The wexel map is mapped toand represents the rectangular surface 1410 of the welding coupon 1400.

FIG. 16 illustrates an example embodiment of a coupon space and a weldspace of a corner (tee joint) welding coupon (WC) 1600 simulated in thesystem 100 of FIG. 1. The corner WC 1600 has two surfaces 1610 and 1620in 3D coupon space that are mapped to 2D weld space as shown in FIG. 16.Again, points O, X, Y, and Z define the local 3D coupon space. Thetexture coordinates of the wexel map are shown as S, T in both 3D couponspace and 2D weld space, in order to clarify the mapping. A user is toweld from point B to point E as shown in FIG. 16. A trajectory line frompoint B to point E is shown in both 3D coupon space and 2D weld space inFIG. 16. However, the direction of displacement is towards the lineX′-O′ as shown in the 3D coupon space, towards the opposite corner asshown in FIG. 16.

FIG. 17 illustrates an example embodiment of a coupon space and a weldspace of a pipe welding coupon (WC) 1700 simulated in the system 100 ofFIG. 1. The pipe WC 1700 has a curved surface 1710 in 3D coupon spacethat is mapped to 2D weld space as shown in FIG. 17. Again, points O, X,Y, and Z define the local 3D coupon space. The texture coordinates ofthe wexel map are shown as S, T in both 3D coupon space and 2D weldspace, in order to clarify the mapping. A user is to weld from point Bto point E along a curved trajectory as shown in FIG. 17. A trajectorycurve and line from point B to point E is shown in 3D coupon space and2D weld space, respectively, in FIG. 17. The direction of displacementis away from the line Y-O (i.e., away from the center of the pipe). FIG.18 illustrates an example embodiment of the pipe welding coupon (WC)1700 of FIG. 17. The pipe WC 1700 is made of a non-ferric,non-conductive plastic and simulates two pipe pieces 1701 and 1702coming together to form a root joint 1703. An attachment piece 1704 forattaching to the arm 173 of the T/S 170 is also shown.

In a similar manner that a texture map may be mapped to a rectangularsurface area of a geometry, a weldable wexel map may be mapped to arectangular surface of a welding coupon. Each element of the weldablemap is termed a wexel in the same sense that each element of a pictureis termed a pixel (a contraction of picture element). A pixel containschannels of information that define a color (e.g., red, green, blue,etc.). A wexel contains channels of information (e.g., P, H, E, D) thatdefine a weldable surface in virtual reality space.

In accordance with an embodiment of the present invention, the format ofa wexel is summarized as channels PHED (Puddle, Heat, Extra,Displacement) which contains four floating point numbers. The Extrachannel is treated as a set of bits which store logical informationabout the wexel such as, for example, whether or not there is any slagat the wexel location. The Puddle channel stores a displacement valuefor any liquefied metal at the wexel location. The Displacement channelstores a displacement value for the solidified metal at the wexellocation. The Heat channel stores a value giving the magnitude of heatat the wexel location. In this way, the weldable part of the coupon canshow displacement due to a welded bead, a shimmering surface “puddle”due to liquid metal, color due to heat, etc. All of these effects areachieved by the vertex and pixel shaders applied to the weldablesurface. In accordance with an alternative embodiment of the presentinvention, a wexel may also incorporate specific metallurgicalproperties that may change during a welding simulation, for example, dueto heat input to the wexel. Such metallurgical properties may be used tosimulate virtual testing and inspection of a weldment.

In accordance with an embodiment of the present invention, adisplacement map and a particle system are used where the particles caninteract with each other and collide with the displacement map. Theparticles are virtual dynamic fluid particles and provide the liquidbehavior of the weld puddle but are not rendered directly (i.e., are notvisually seen directly). Instead, only the particle effects on thedisplacement map are visually seen. Heat input to a wexel affects themovement of nearby particles. There are two types of displacementinvolved in simulating a welding puddle which include Puddle andDisplacement. Puddle is “temporary” and only lasts as long as there areparticles and heat present. Displacement is “permanent”. Puddledisplacement is the liquid metal of the weld which changes rapidly(e.g., shimmers) and can be thought of as being “on top” of theDisplacement. The particles overlay a portion of a virtual surfacedisplacement map (i.e., a wexel map). The Displacement represents thepermanent solid metal including both the initial base metal and the weldbead that has solidified.

In accordance with an embodiment of the present invention, the simulatedwelding process in virtual reality space works as follows: Particlesstream from the emitter (emitter of the simulated MWT 160) in a thincone. The particles make first contact with the surface of the simulatedwelding coupon where the surface is defined by a wexel map. Theparticles interact with each other and the wexel map and build up inreal-time. More heat is added the nearer a wexel is to the emitter. Heatis modeled in dependence on distance from the arc point and the amountof time that heat is input from the arc. Certain visuals (e.g., color,etc.) are driven by the heat. A weld puddle is drawn or rendered invirtual reality space for wexels having enough heat. Wherever it is hotenough, the wexel map liquefies, causing the Puddle displacement to“raise up” for those wexel locations. Puddle displacement is determinedby sampling the “highest” particles at each wexel location. As theemitter moves on along the weld trajectory, the wexel locations leftbehind cool. Heat is removed from a wexel location at a particular rate.When a cooling threshold is reached, the wexel map solidifies. As such,the Puddle displacement is gradually converted to Displacement (i.e., asolidified bead). Displacement added is equivalent to Puddle removedsuch that the overall height does not change. Particle lifetimes aretweaked or adjusted to persist until solidification is complete. Certainparticle properties that are modeled in the system 100 includeattraction/repulsion, velocity (related to heat), dampening (related toheat dissipation), direction (related to gravity).

FIGS. 19A-19C illustrate an example embodiment of the concept of adual-displacement (displacement and particles) puddle model of thesystem 100 of FIG. 1. Welding coupons are simulated in virtual realityspace having at least one surface. The surfaces of the welding couponare simulated in virtual reality space as a double displacement layerincluding a solid displacement layer and a puddle displacement layer.The puddle displacement layer is capable of modifying the soliddisplacement layer.

As described herein, “puddle” is defined by an area of the wexel mapwhere the Puddle value has been raised up by the presence of particles.The sampling process is represented in FIGS. 19A-19C. A section of awexel map is shown having seven adjacent wexels. The currentDisplacement values are represented by un-shaded rectangular bars 1910of a given height (i.e., a given displacement for each wexel). In FIG.19A, the particles 1920 are shown as round un-shaded dots colliding withthe current Displacement levels and are piled up. In FIG. 19B, the“highest” particle heights 1930 are sampled at each wexel location. InFIG. 19C, the shaded rectangles 1940 show how much Puddle has been addedon top of the Displacement as a result of the particles. The weld puddleheight is not instantly set to the sampled values since Puddle is addedat a particular liquification rate based on Heat. Although not shown inFIGS. 19A-19C, it is possible to visualize the solidification process asthe Puddle (shaded rectangles) gradually shrink and the Displacement(un-shaded rectangles) gradually grow from below to exactly take theplace of the Puddle. In this manner, real-time molten metal fluiditycharacteristics are accurately simulated. As a user practices aparticular welding process, the user is able to observe the molten metalfluidity characteristics and the heat dissipation characteristics of theweld puddle in real-time in virtual reality space and use thisinformation to adjust or maintain his welding technique.

The number of wexels representing the surface of a welding coupon isfixed. Furthermore, the puddle particles that are generated by thesimulation to model fluidity are temporary, as described herein.Therefore, once an initial puddle is generated in virtual reality spaceduring a simulated welding process using the system 100, the number ofwexels plus puddle particles tends to remain relatively constant. Thisis because the number of wexels that are being processed is fixed andthe number of puddle particles that exist and are being processed duringthe welding process tend to remain relatively constant because puddleparticles are being created and “destroyed” at a similar rate (i.e., thepuddle particles are temporary). Therefore, the processing load of thePPS 110 remains relatively constant during a simulated welding session.

In accordance with an alternate embodiment of the present invention,puddle particles may be generated within or below the surface of thewelding coupon. In such an embodiment, displacement may be modeled asbeing positive or negative with respect to the original surfacedisplacement of a virgin (i.e., un-welded) coupon. In this manner,puddle particles may not only build up on the surface of a weldingcoupon, but may also penetrate the welding coupon. However, the numberof wexels is still fixed and the puddle particles being created anddestroyed is still relatively constant.

In accordance with alternate embodiments of the present invention,instead of modeling particles, a wexel displacement map may be providedhaving more channels to model the fluidity of the puddle. Or, instead ofmodeling particles, a dense voxel map may be modeled. Or, instead of awexel map, only particles may be modeled which are sampled and never goaway. Such alternative embodiments may not provide a relatively constantprocessing load for the system, however.

Furthermore, in accordance with an embodiment of the present invention,blowthrough or a keyhole is simulated by taking material away. Forexample, if a user keeps an arc in the same location for too long, inthe real world, the material would burn away causing a hole. Suchreal-world burnthrough is simulated in the system 100 by wexeldecimation techniques. If the amount of heat absorbed by a wexel isdetermined to be too high by the system 100, that wexel may be flaggedor designated as being burned away and rendered as such (e.g., renderedas a hole). Subsequently, however, wexel re-constitution may occur forcertain welding process (e.g., pipe welding) where material is addedback after being initially burned away. In general, the system 100simulates wexel decimation (taking material away) and wexelreconstitution (i.e., adding material back). Furthermore, removingmaterial in root-pass welding is properly simulated in the system 100.

Furthermore, removing material in root-pass welding is properlysimulated in the system 100. For example, in the real world, grinding ofthe root pass may be performed prior to subsequent welding passes.Similarly, system 100 may simulate a grinding pass that removes materialfrom the virtual weld joint. It will be appreciated that the materialremoved may be modeled as a negative displacement on the wexel map. Thatis to say that the grinding pass removes material that is modeled by thesystem 100 resulting in an altered bead contour. Simulation of thegrinding pass may be automatic, which is to say that the system 100removes a predetermined thickness of material, which may be respectiveto the surface of the root pass weld bead.

In an alternative embodiment, an actual grinding tool, or grinder, maybe simulated that turns on and off by activation of the mock weldingtool 160 or another input device. It is noted that the grinding tool maybe simulated to resemble a real world grinder. In this embodiment, theuser maneuvers the grinding tool along the root pass to remove materialresponsive to the movement thereof. It will be understood that the usermay be allowed to remove too much material. In a manner similar to thatdescribed above, holes or other defects (described above) may result ifthe user grinds away too much material. Still, hard limits or stops maybe implemented, i.e. programmed, to prevent the user from removing toomuch material or indicate when too much material is being removed.

In addition to the non-visible “puddle” particles described herein, thesystem 100 also uses three other types of visible particles to representArc, Flame, and Spark effects, in accordance with an embodiment of thepresent invention. These types of particles do not interact with otherparticles of any type but interact only with the displacement map. Whilethese particles do collide with the simulated weld surface, they do notinteract with each other. Only Puddle particles interact with eachother, in accordance with an embodiment of the present invention. Thephysics of the Spark particles is setup such that the Spark particlesbounce around and are rendered as glowing dots in virtual reality space.

The physics of the Arc particles is setup such that the Arc particleshit the surface of the simulated coupon or weld bead and stay for awhile. The Arc particles are rendered as larger dim bluish-white spotsin virtual reality space. It takes many such spots superimposed to formany sort of visual image. The end result is a white glowing nimbus withblue edges.

The physics of the Flame particles is modeled to slowly raise upward.The Flame particles are rendered as medium sized dim red-yellow spots.It takes many such spots superimposed to form any sort of visual image.The end result is blobs of orange-red flames with red edges raisingupward and fading out. Other types of non-puddle particles may beimplemented in the system 100, in accordance with other embodiments ofthe present invention. For example, smoke particles may be modeled andsimulated in a similar manner to flame particles.

The final steps in the simulated visualization are handled by the vertexand pixel shaders provided by the shaders 117 of the GPUs 115 (see FIG.11). The vertex and pixel shaders apply Puddle and Displacement, as wellas surface colors and reflectivity altered due to heat, etc. The Extra(E) channel of the PHED wexel format, as discussed earlier herein,contains all of the extra information used per wexel. In accordance withan embodiment of the present invention, the extra information includes anon virgin bit (true=bead, false=virgin steel), a slag bit, an undercutvalue (amount of undercut at this wexel where zero equals no undercut),a porosity value (amount of porosity at this wexel where zero equals noporosity), and a bead wake value which encodes the time at which thebead solidifies. There are a set of image maps associated with differentcoupon visuals including virgin steel, slag, bead, and porosity. Theseimage maps are used both for bump mapping and texture mapping. Theamount of blending of these image maps is controlled by the variousflags and values described herein.

A bead wake effect is achieved using a 1D image map and a per wexel beadwake value that encodes the time at which a given bit of bead issolidified. Once a hot puddle wexel location is no longer hot enough tobe called “puddle”, a time is saved at that location and is called “beadwake”. The end result is that the shader code is able to use the 1Dtexture map to draw the “ripples” that give a bead its unique appearancewhich portrays the direction in which the bead was laid down. Inaccordance with an alternative embodiment of the present invention, thesystem 100 is capable of simulating, in virtual reality space, anddisplaying a weld bead having a real-time weld bead wake characteristicresulting from a real-time fluidity-to-solidification transition of thesimulated weld puddle, as the simulated weld puddle is moved along aweld trajectory.

In accordance with an alternative embodiment of the present invention,the system 100 is capable of teaching a user how to troubleshoot awelding machine. For example, a troubleshooting mode of the system maytrain a user to make sure he sets up the system correctly (e.g., correctgas flow rate, correct power cord connected, etc.) In accordance withanother alternate embodiment of the present invention, the system 100 iscapable of recording and playing back a welding session (or at least aportion of a welding session, for example, N frames). A track ball maybe provided to scroll through frames of video, allowing a user orinstructor to critique a welding session. Playback may be provided atselectable speeds as well (e.g., full speed, half speed, quarter speed).In accordance with an embodiment of the present invention, asplit-screen playback may be provided, allowing two welding sessions tobe viewed side-by-side, for example, on the ODD 150. For example, a“good” welding session may be viewed next to a “poor” welding sessionfor comparison purposes.

As discussed earlier herein, a standalone virtual weldment inspection(VWI) system is capable of inputting a predefined virtual weldment or avirtual weldment created using the VRAW system, and performing virtualinspection of the virtual weldment. However, unlike the VRAW system, theVWI system may not be capable of creating a virtual weldment as part ofa simulated virtual welding process, and may or may not be capable ofperforming virtual destructive/non-destructive testing of that weldment,in accordance with certain embodiments of the present invention.

FIG. 20 illustrates an example embodiment of a standalone virtualweldment inspection (VWI) system 2000 capable of simulating inspectionof a virtual weldment and displaying an animation of the virtualweldment under inspection to observe the effects due to variouscharacteristics associated with the weldment. In one embodiment the VWIsystem 2000 includes a programmable processor-based subsystem (PPS)2010, similar to the PPS 110 of FIG. 1. The VWI system 2000 furtherincludes an observer display device (ODD) 2050, similar to the ODD 150of FIG. 1, operatively connected to the PPS 2010. The VWI system 2000also includes a keyboard 2020 and a mouse 2030 operatively connected tothe PPS 2010.

In a first embodiment of the system 2000 of FIG. 20, the PPS 110provides hardware and software configured as a rendering engine forproviding 3D animated renderings of virtual weldments. The PPS 110 alsoprovides hardware and software configured as an analysis engine forperforming testing and inspection of a virtual weldment. The PPS 2010 iscapable of inputting data representative of a virtual weldment andgenerating an animated 3D rendering of the virtual weldment forinspection using a rendering engine of the PPS 110 operating on theinput data. The virtual weldment data may be “pre-canned” (i.e.pre-defined) virtual weldments (e.g., generated using a separatecomputer system) or virtual weldment data created using a virtualreality welding simulator system (e.g., a VRAW system as previouslydescribed herein).

Furthermore, in accordance with an enhanced embodiment of the presentinvention, the PPS 2010 includes an advancedanalysis/rendering/animation capability that allows the VWI system 2000to perform a virtual destructive/non-destructive test on an inputvirtual weldment and display an animation of the test, similar to thatof the VRAW system.

In accordance with an embodiment of the present invention, a virtualrendering of a weldment created using a VRAW system in exported the VWIsystem. A testing portion of the VWI system is capable of automaticallygenerating cut sections of the virtual weldment and submitting those cutsections (or the uncut virtual weldment itself) to one of a plurality ofpossible destructive and non-destructive tests within the testingportion of the VWI system. Each of the plurality of tests is capable ofgenerating an animation illustrating that particular test. The VWIsystem is capable of displaying the animation of the test to the user.The animation clearly shows to the user whether or not the virtualweldment generated by the user passes the test.

For example, a virtual weldment that is subjected to a virtual bend testmay be shown to break in the animation at a location where a particulartype of defect occurs in the weld joint of the virtual weldment. Asanother example, a virtual weldment that is subjected to a virtual bendtest may be shown to bend in the animation and crack or show asignificant amount of defect, even though the weldment does notcompletely break. The same virtual weldment may be tested over and overagain for different tests using the same cut sections (e.g., the cutsections may be reconstituted by the VWI system) or different cutsections of the virtual weldment. In accordance with an embodiment ofthe present invention, a virtual weldment is tagged with metallurgicalcharacteristics such as, for example, type of metal and tensile strengthwhich are factored into the particular selecteddestructive/non-destructive test.

In accordance with an embodiment of the present invention, a backgroundrunning expert system may pop up in a window on a display of the VWIsystem and indicate to the user (e.g., via a text message and/orgraphically) why the weldment failed the test (e.g., too much porosityat these particular points in the weld joint) and what particularwelding standard(s) was not met. In accordance with another embodimentof the present invention, the VWI system may hyper-text link to anexternal tool that ties the present test to a particular weldingstandard.

In accordance with an embodiment of the present invention, the animationof a particular destructive/non-destructive test is a 3D rendering ofthe virtual weldment as modified by the test such that a user may movethe rendered virtual weldment around in a three-dimensional manner on adisplay of the VWI system during the test to view the test from variousangles and perspectives. The same 3D rendered animation of a particulartest may be played over and over again to allow for maximum trainingbenefit for the same user or for multiple users.

In a simpler, less complex embodiment of the VWI system 2000 of FIG. 20,the PPS 2010 is capable of inputting an animated 3D rendering of avirtual destructive or non-destructive test generated by a VRAW system,and displaying the animation for inspection purposes. The PPS 2010provides hardware and software configured as an analysis engine forperforming inspection of a virtual weldment. However, in this simplerembodiment, the PPS 2010 does not provide hardware and softwareconfigured as a rendering engine for providing 3D animated renderings ofvirtual weldments, and the analysis engine is limited to supportinginspection of a virtual weldment. The renderings and testing are doneelsewhere (e.g., on a VRAW system) and are input to the VWI system insuch an embodiment. In such a simpler embodiment, the PPS 2010 may be astandard, off-the-shelf personal computer or work station programmedwith software to perform virtual inspection and to train with respect towelding inspection.

As previously discussed herein, virtual inspection may be implemented onthe VWI system in any of a number of different ways and/or combinationsthereof. In accordance with one embodiment of the present invention, theVWI system includes an expert system and is driven by a set of rules. Inaccordance with another embodiment of the present invention, the VWIsystem includes support vector machines. In accordance with still afurther embodiment of the present invention, the VWI system includes aneural network that is capable of being trained and adapted to newscenarios, and/or intelligent agents that provide feedback to a studentconcerning areas where the student needs more practice, or to providefeedback to an instructor or educator as to how to modify the teachingcurriculum to improve student learning. Furthermore, a user may haveaccess to a knowledge base which includes text, pictures, video, anddiagrams to support their training.

In accordance with an embodiment of the present invention, a renderedvirtual weldment and/or a corresponding 3D rendered animation of thevirtual weldment under test may be input to the VWI system to perform aninspection of the weld and/or to train a user in welding inspection(e.g., for becoming a certified welding inspector). The inspectionportion of the system includes a teaching mode and a training mode.

In the teaching mode, the virtual weldment and/or the 3D renderedanimation of a virtual weldment under test is displayed and viewed by agrader (trainer) along with a welding student. The trainer and thewelding student are able to view and interact with the virtual weldment.The trainer is able to make a determination (e.g., via a scoring method)how well the welding student performed at identifying defects anddiscontinuities in the virtual weldment, and indicate to the weldingstudent how well the welding student performed and what the studentmissed by interacting with the displayed virtual weldment (viewing fromdifferent perspectives, etc.).

In the training mode, the system asks a welding inspector studentvarious questions about the virtual weldment and allows the weldinginspector student to input answers to the questions. The system mayprovide the welding inspector student with a grade at the end of thequestioning. For example, the system may initially provide samplequestions to the welding inspector student for one virtual weldment andthen proceed to provide timed questions to the welding inspector studentfor another virtual weldment which is to be graded.

The inspection portion of the system may also provide certaininteractive tools that help a welding inspector student or trainer todetect defects and make certain measurements on the virtual weld whichare compared to predefined welding standards (e.g., a virtual guage thatmeasures, for example, penetration of a root weld and compares themeasurement to a required standard penetration). Grading of a weldinginspector student may also include whether or not the welding inspectorstudent uses the correct interactive tools to evaluate the weld. Inaccordance with an embodiment of the present invention, the inspectionportion of the system, based on grading (i.e., scoring) determines whichareas the welding inspector student needs help and provides the weldinginspector student with more representative samples upon which topractice inspecting.

Again, the various interactive inspection tools may be used on eitherthe virtual weldment before being subjected to testing, the virtualweldment after being subjected to testing, or both. The variousinteractive inspection tools and methodologies are configured forvarious welding processes, types of metals, and types of weldingstandards, in accordance with an embodiment of the present invention. Onthe standalone VWI system 2000, the interactive inspection tools may bemanipulated using a keyboard 2020 and mouse 2030, for example. Otherexamples of interactive inspection tools include a virtual Palmgrenguage for performing a throat measurement, a virtual fillet gauge fordetermining leg size, a virtual VWAC guage for performing a convexitymeasurement or measurement of undercut, a virtual sliding caliper formeasuring the length of a crack, a virtual micrometer for measuring thewidth of a crack, and a virtual magnifying lens for magnifying a portionof a weld for inspection. Other virtual interactive inspection tools arepossible as well, in accordance with various embodiments of the presentinvention.

FIG. 21 illustrates a flow chart of an example embodiment of a method2100 to assess the quality of a rendered baseline virtual weldment invirtual reality space. In step 2110, a baseline virtual weldment isrendered (or rendered again . . . re-rendered). For example, a user mayemploy the VRAW system 100 to practice his welding technique on avirtual part and render the baseline virtual weldment, beingrepresentative of the user's welding ability. As used herein, the term“virtual weldment” may refer to the entire virtual welded part or avirtual cut section thereof, as is used in many welding tests.

In step 2120, the baseline virtual weldment is subjected to acomputer-simulated test (e.g., a destructive virtual test or anon-destructive virtual test) configured to test a characteristic(s) ofthe baseline virtual weldment. The computer-simulated test may beperformed by the VRAW system or the VWI system, for example. In step2130, in response to the simulated testing, a tested virtual weldment isrendered (e.g., a modification of the baseline virtual weldment due todestructive testing) and associated test data is generated. In step2140, the tested virtual weldment and the test data is subjected to acomputer-simulated analysis. The computer-simulated analysis isconfigured to determine pass/fail conditions of the tested virtualweldment with respect to the characteristic(s) of the virtual weldment.For example, a determination may be made as to whether or not thevirtual weldment passed a bend test, based on analysis of thecharacteristic(s) after the test.

In step 2150, a decision is made by the user to inspect the testedvirtual weldment or not. If the decision is not to inspect then, in step2160, a decision is made as to performing another test or not. If thedecision is made to perform another test, then the method reverts backto step 2110 and the baseline virtual weldment is re-rendered, as if theprevious test did not take place on the virtual weldment. In thismanner, many tests (destructive and non-destructive) can be run on thesame baseline virtual weldment and analyzed for various pass/failconditions. In step 2150, if the decision is to inspect then, in step2170, the tested virtual weldment (i.e., the virtual weldment aftertesting) is displayed to the user and the user may manipulate theorientation of the tested virtual weldment to inspect variouscharacteristics of the tested virtual weldment. In step 2180, the usermay access and apply programmed inspection tools to the tested virtualweldment to aid in the inspection. For example, a user may access avirtual guage that measures penetration of a root weld and compares themeasurement to a required standard penetration. After inspection, againin step 2160, the decision is made to perform another test or not. Ifanother test is not to be performed, then the method ends.

As an example, a same cut section of a virtual weldment 2200 may besubjected to a simulated bend test, a simulated tensile or pull test,and a simulated nick break test as shown in FIGS. 22-24, respectively.Referring to FIG. 22, a straight cut section of a virtual weldment 2200having a weld joint 2210 is subject to a simulated bend test. The bendtest may be performed to find various weld properties such as ductilityof the welded zone, weld penetration, fusion, crystalline structure (ofthe fractured surface), and strength. The bend test helps to determinethe quality of the weld metal, the weld junction, and the heat affectedzone. Any cracking of the metal during the bend test indicates poorfusion, poor penetration, or some other condition that can causecracking. Stretching of the metal helps indicate the ductility of theweld. A fractured surface reveals the crystalline structure of the weld.Larger crystals tend to indicate a defective welding procedure orinadequate heat treatment after welding. A quality weld has smallcrystals.

Referring to FIG. 23, after the bend test, the same straight cut sectionof the virtual weldment 2200 having the same weld joint 2210 may bere-rendered and subject to a simulated pull test. The pull test (ortensile test) may be performed to find the strength of a welded joint.In the simulated test, the virtual weldment 2200 is held on one end andpulled on the other end until the virtual weldment 2200 breaks. Thetensile load or pull, at which the weldment 2200 breaks, is determinedand may be compared to a standard measure for pass/fail determination.

Referring to FIG. 24, after the pull test, the same straight cut sectionof the virtual weldment 2200 having the same weld joint 2210 may bere-rendered and subject to a simulated nick break test. The simulatednick break test is performed to determine if the weld metal of a weldedbutt joint has any internal defects such as, for example, slaginclusion, gas pockets, poor fusion, and oxidized metal. A slot is cutinto each side of the weld joint 2210 as shown in FIG. 24. The virtualweldment 2200 is positioned across two supports and struck with a hammeruntil the section of the weld 2210 between the slots fractures. Theinternal metal of the weld 2210 may be inspected for defects. Defectsmay be compared to standard measures for pass/fail determination.

While the claimed subject matter of the present application has beendescribed with reference to certain embodiments, it will be understoodby those skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope of theclaimed subject matter. In addition, many modifications may be made toadapt a particular situation or material to the teachings of the claimedsubject matter without departing from its scope. Therefore, it isintended that the claimed subject matter not be limited to theparticular embodiments disclosed, but that the claimed subject matterwill include all embodiments falling within the scope of the appendedclaims.

1. A system for the virtual testing and inspecting of a virtualweldment, said system comprising: a programmable processor-basedsubsystem operable to execute coded instructions, said codedinstructions including: a rendering engine configured to render at leastone of a three-dimensional (3D) virtual weldment before simulatedtesting, a 3D animation of a virtual weldment under simulated testing,and a 3D virtual weldment after simulated testing, and an analysisengine configured to perform simulated testing of a 3D virtual weldment,and further configured to perform inspection of at least one of a 3Dvirtual weldment before simulated testing, a 3D animation of a virtualweldment under simulated testing, and a 3D virtual weldment aftersimulated testing for at least one of pass/fail conditions anddefect/discontinuity characteristics; at least one display deviceoperatively connected to said programmable processor-based subsystem fordisplaying at least one of a 3D virtual weldment before simulatedtesting, a 3D animation of a virtual weldment under simulated testing,and a 3D virtual weldment after simulated testing; and a user interfaceoperatively connected to said programmable processor-based subsystem andconfigured for at least manipulating an orientation of at least one of a3D virtual weldment before simulated testing, a 3D animation of avirtual weldment under simulated testing, and a 3D virtual weldmentafter simulated testing on said at least one display device.
 2. Thesystem of claim 1, wherein said programmable processor-based subsystemincludes a central processing unit and at least one graphics processingunit.
 3. The system of claim 2, wherein said at least one graphicsprocessing unit includes a computer unified device architecture (CUDA)and a shader.
 4. The system of claim 1, wherein said analysis engineincludes at least one of an expert system, a support vector machine(SVM), a neural network, and an intelligent agent.
 5. The system ofclaim 1 wherein said analysis engine uses welding code data or weldingstandards data to analyze at least one of a 3D virtual weldment beforesimulated testing, a 3D animation of a virtual weldment under simulatedtesting, and a 3D virtual weldment after simulated testing.
 6. Thesystem of claim 1 wherein said analysis engine includes programmedvirtual inspection tools that can be accessed and manipulated by a userusing said user interface to inspect a virtual weldment.
 7. The systemof claim 1 wherein said simulated testing includes at least one ofsimulated destructive testing and simulated non-destructive testing. 8.A virtual welding testing and inspecting simulator, said simulatorcomprising: means for performing one or more simulated destructive andnon-destructive tests on a rendered 3D virtual weldment; means foranalyzing results of said one or more simulated destructive andnon-destructive tests on said rendered 3D virtual weldment; and meansfor inspecting said rendered 3D virtual weldment at least after asimulated test of said 3D virtual weldment.
 9. The simulator of claim 8further comprising means for rendering a 3D virtual weldment.
 10. Thesimulator of claim 8 further comprising means for rendering a 3Danimation of said virtual weldment while performing said one or moresimulated destructive and non-destructive tests.
 11. The simulator ofclaim 10 further comprising means for displaying and manipulating anorientation of said 3D animation of said virtual weldment.
 12. Thesimulator of claim 8 further comprising means for inspecting a 3Dvirtual weldment before, during, and after simulated testing of said 3Dvirtual weldment.
 13. A method of assessing the quality of a renderedbaseline virtual weldment in virtual reality space, said methodcomprising: subjecting said baseline virtual weldment to a firstcomputer-simulated test configured to test at least one characteristicof said baseline virtual weldment; rendering a first tested virtualweldment and generating first test data in response to said first test;and subjecting said first tested virtual weldment and said first testdata to a computer-simulated analysis configured to determine at leastone pass/fail condition of said first tested virtual weldment withrespect to said at least one characteristic.
 14. The method of claim 13,wherein said first computer-simulated test simulates a real-worlddestructive test.
 15. The method of claim 13, wherein said firstcomputer-simulated test simulates a real-world non-destructive test. 16.A method of claim 13 further comprising: re-rendering said baselinevirtual weldment in virtual reality space; subjecting said baselinevirtual weldment to a second computer-simulated test configured to testat least one other characteristic of said baseline virtual weldment;rendering a second tested virtual weldment and generating second testdata in response to said second test; and subjecting said second testedvirtual weldment and said second test data to a computer-simulatedanalysis configured to determine at least one other pass/fail conditionof said second tested virtual weldment with respect to said at least oneother characteristic.
 17. The method of claim 16, wherein said secondcomputer-simulated test simulates a real-world destructive test.
 18. Themethod of claim 16, wherein said second computer-simulated testsimulates a real-world non-destructive test.
 19. The method of claim 13further comprising manually inspecting a displayed version of saidrendered first tested virtual weldment.
 20. The method of claim 16further comprising manually inspecting a displayed version of saidrendered second tested virtual weldment.